As background art for enhancing efficiency and output of a rotary electric machine, for example, Patent Document 1 is proposed. In Patent Document 1, a width adjustment portion is provided so that the circumferential direction width of each slot between stator teeth is narrowed inwardly in the radial direction, thereby reducing a difference in magnetic resistance in the radial direction of each tooth, and enhancing performance of the rotary electric machine.
In order to enable insertion into the slot having the width adjustment portion, a stator coil is substantially formed into a U shape so as to have two straight portions and a connection portion connecting them, a cross section of each straight portion of the stator coil is shaped into a shape along the width adjustment portion, and both radial direction ends of the straight portion are shaped into a shape along a direction perpendicular to the radial direction. Then, the stator coil is inserted and placed in the slot from the axial direction thereof. Thus, a gap between the stator coil and the slot is narrowed, whereby a space factor of a stator can be improved.